What are a couple social reasons for immigration? i also need political and economic reasons too

Which events are correlated but do not necessarily have a causal relationship?

How did the boston massacre contribute to the writing of the declaration of independence? a. many colonists began to see the british government as a source of protection. b. many colonists began to see the british government as a supporter of free speech. c. many colonists began to oppose the british government's building of forts on the frontier. d. many colonists began to fear the british government's harsh actions toward the colonies.

What was unification difficult to accomplish in both germany and italy? a.) weaker states we’re attacked by stronger states for control of the emerging nations. b.) major european powers fought to keep independent states under their control. c.) germans and italians did not share common histories and languages.